At Chatham House, Leslie leads research on the U.S. and International Order, and a multi partner initiative on Reimagining Multilateralism. Her recent publications include ‘Why Multilateralism Still Matters’ (Foreign Affairs, October 2023, and Building Global Prosperity: Proposals for Sustainable Growth (Chatham House, 2022). The latter was the result of a multi-authored Chatham House initiative supported by the Rockefeller Foundation that looked at G7 proposals for countering China’s influence in the developing world. 

She is co-editor and contributing author (with Charles A. Kupchan) of Anchoring the World: International Order in the 21st Century, a publication by members of the Lloyd George Study Group on World Order, a joint Centenary project of Chatham House, the Council on Foreign Relations, and Georgetown University’s School of Foreign Service, published by Foreign Affairs. Also Human Rights Futures (Cambridge University Press, 2017), US Foreign Policy Priorities (Chatham House, 2020), and ’Trials and Errors: Strategies of International Justice” (with Jack Snyder). 

She is a regular commentator in the international news media and has contributed pieces in the Financial Times, Guardian, Sunday Times, Telegraph, and the Independent. 

She is deputy chair of the Marshall Aid Commemoration Commission and a trustee of the Carnegie Council for Ethics and International Affairs.

She is a life member of the Council on Foreign Relations, and on the Advisory Board of LSE IDEAS and the LSE Phelan United States Centre, and is vice president of the board for the Institute for Integrated Transitions.

From 2014-2016 she was director of the Center on Conflict, Rights and Justice (and previously co-director). She was previously on the academic faculty of Georgetown University’s School of Foreign Service, and a fellow of the John M. Olin Institute at Harvard University.

She began her career at Congressional Research Service and also worked in the Asia Bureau at USAID. Leslie received a BA from Wesleyan University (Phi Beta Kappa), an MSc (Distinction) from the London School of Economics, and a PhD from Columbia University.